The large scale processing of pod vegetables forms an important part of the operation of vegetable canneries and similar businesses. Pod vegetables such as beans or peas typically are picked in such a way that many of the pods are still joined by their stems to form clusters. The clusters must be broken up into individual pods, the flower and stem ends of the pods commonly must be snipped off, the pods may be graded for size, and so forth.
Many of the machines that have been developed to perform these operations employ a rotating drum within which the pod vegetables are tumbled. The pod vegetables interact with the interior surfaces of the drum as part of the functioning of the machine. Thus, clusters may be engaged by hooks formed in the drum's inner surface to be drawn past knives that cut the stems of the clusters and separate the individual pods. In snipping machines the ends of the pods commonly are directed outwardly through openings in the inner surface of the drum to project therethrough and be snipped by knives sliding over the exterior surface of the drum. Pods may be graded for size by being seived through openings in the surface of a drum that have a particular size. Commonly such grading machines run more efficiently if the pods are directed toward the openings end first.
Those skilled in the art are generally cognizant of the use of baffles, vanes, and the like to tip a pod so that one of its ends engages the interior surface of a drum. Such vanes typically extend inwardly from the inner surfaces of the drum.
Buck, U.S. Pat. No. 1,990,425; Finley, U.S. Pat. No. 2,393,461; and Burton, U.S. Pat. No. 4,213,383, all are examples of bean snippers of the sort described above in which the end of the bean must project through an opening in the drum to be snipped off by a knife sliding over the outer surface of the drum. Each of these patents show devices contained within the drum adapted to orient beans endwardly toward the inner surface of the drum. In Buck, rods are provided extending the length of the drum that serve to break up any roped mass of beans, allowing the beans to tumble more freely so as to be presented endwardly toward the inner surface of the drum. In Finley, beans in the rotating drum are carried upwardly by the drum and thrown against a vertically corrugated surface so that beans sliding downwardly in the troughs of the corrugation may tend to be endwardly presented to the inner surface of the drum as the beans reach the bottom of the drum.
In Burton, beans are thrown by the rotating drum against an orientor having a plurality of circular disks mounted perpendicularly on a shaft having its axis substantially parallel to the axis of the drum. The disks rotate in the same direction as the drum rotates. Beans falling between the disks are oriented so that the longitudinal axis of each bean lies within a plane perpendicular to the axis of the drum. The openings in the drum of the bean snipper of Burton through which the beans must extend to be snipped are longitudinally extended within like planes, so the beans as they emerge from the orientor at the bottom of the drum are aligned with the openings and have an improved chance of extending therethrough. Although some lesser percentage of the beans encounters the orientor discs at such an angle thereto that they cannot slide between the discs and instead are thrown toward the descending side of the drum to contact the drum structure through a greater arc of its travel, it can be seen that those beans which are so thrown are not oriented by the action of the discs, and those which are oriented are not effectively thrown to the descending side of the drum.
A number of drum-type pod vegetable processing machines have various other devices located within their drums, extending lengthwise therethrough. Examples include Arve, et al., U.S. Pat. No. 3,645,271; Farrow, U.S. Pat. No. 3,601,171; Burton, U.S. Pat. No. 3,059,648; Frova, U.S. Pat. No. 2,693,834; and Toner, U.S. Pat. No. 144,486. These structures serve such functions as pressing pods being processed against the interior of the drum and removing pods or trash. Included in the patents referred to are some machines generally similar to pod vegetable handling machines but in fact designed to process corn or other food materials.
One feature of drum-type pod vegetable processing machines that follows naturally from the principles of their operation is that a considerable portion of the interior surface of the drum is not in contact with the pods at any given instant. Instead, the pods lie in the bottom of the drum to be tumbled or thrown in a manner dictated by the interior features of the drum. Because such a machine works on the pod vegetables by interaction between the pods and the interior surfaces of the drum, attempts have been made to increase the area of the inner surface of the drum that is in contact with the pod vegetables to increase the capacity and efficiency of the machine. Thus, increases in the diameter of the drum make for a broader, flatter area of inner surface capable of contacting the pods. One effect of increasing diameter is that pods carried upwardly by the drum may fall a considerable distance to the floor of the drum, with some increase of bruising and breakage of the pods.